1 #include <stdlib.h> 2 #include <string.h> 3 #include <stdint.h> 4 5 static const char digits[] = 6 "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"; 7 8 long a64l(const char *s) 9 { 10 int e; 11 uint32_t x = 0; 12 for (e=0; e<36 && *s; e+=6, s++) { 13 const char *d = strchr(digits, *s); 14 if (!d) break; 15 x |= (uint32_t)(d-digits)<<e; 16 } 17 return (int32_t)x; 18 } 19 20 char *l64a(long x0) 21 { 22 static char s[7]; 23 char *p; 24 uint32_t x = x0; 25 for (p=s; x; p++, x>>=6) 26 *p = digits[x&63]; 27 *p = 0; 28 return s; 29 } 30